Origami steel yacht construction

Discussion in 'Metal Boat Building' started by origamiboats, Nov 30, 2001.

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  1. LyndonJ
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    LyndonJ Senior Member

    Yeah the overalll shape is, by an inch or two here and there, but you can't see whats inside.

    What size was the Baja boat?
    So the same owner run it aground and then self recovered it ? How long was it ashore and we'd love to see the picture please.
     
  2. junk2lee
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    junk2lee Junior Member

    Further,to LyndonJ,quote:
    "Real statistics like:
    How many Brent built as-designed 36 boats with the poor keel supporting frames have done passages and been washed over reefs and pounded on hard beaches…………."

    I don't think many boats are designed on those criteria except landing craft.I wouldn't want to take that guarantee on if I were a designer...or is this an inquest without a corpse?

    In fact,there is a lot of information for the homebuilder of Brent boats supplementary to Brent's willing help. There's a very popular forum on yahoo with tons and tons of help.

    Terho,per
    "This "one-off" phenomenon is a direct result of not having decent drawings and documentation. When there is no detailed drawings, the builders start to create their own ideas. This can be hazardous. I can show one extremely dangerous structure; the strut (pillar) which should lead the mast compression to the hull structure is in some boats welded direct to bottom shell and not to stiffener or floor! (a floor is not the same in boat and home)"

    Well,I agree.that ain't pretty."Dangerous"is a stretch from this photo.I can't see from this if the mast is in a tabernacle or keel stepped.Deck-stepped on a cambered deck with strong set of beams would make this detail(per photo)inconsequential.Perhaps it's for a handhold or furniture.If the mast is keel-stepped,it's still inconsequential.It looks more "lets tack this in for the interior woodwork" to me but I could be wrong.I can't see the deck in this picture.
    The boat is not finished either so what happened after?Maybe it all changed before launching.
     
  3. junk2lee
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    junk2lee Junior Member

    BrentBoat on beach

    Here.
    mungo in mexico moves.jpg

    mungo inmexico+rudy.jpg
     
  4. junk2lee
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    junk2lee Junior Member

    And again.

    mungowreckagain.jpg

    And there she still is,unless someone pulled her out.
     
  5. LyndonJ
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    LyndonJ Senior Member

    No just a marketing line, probably not much else.

    Thanks for the pics, great effort.

    So the first time she washed ashore she was got off quickly with self rescue , and the second time she stayed for ever ?

    The Poor owner . It would be a nightmare to awake to that bump !

    That's a 21 footer isn't it?
     
  6. junk2lee
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    junk2lee Junior Member

    I think you can see that it's bigger than 21 feet plain enough.I would say very very very near 36.
    As an aside,it was the owner's two friends,Norm+Rudy that immediately went down from Canada and with generous help from the Steelworkers Union(for the gear)and the local people too set about the rescue.I can't remember exactly if it took more than a week to haul her but it needed tides and fair weather on the final pull.

    Norm built a BrentBoat too.Rudy Brentified an existing hull design.Brentify would mean "in form before frame"and "welded flat before shape" in this instance and coined for this post alone.If you know what it is,congratulations.You're now inducted into the cult.:rolleyes:
     
  7. Brent Swain
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    Brent Swain Member

    As I have told you many times "I have never designed a 21 footer" What part of "NEVER" don't you understand?
    Duuuhhh!!
    That is a 36, the first origami 36 I ever built, which pounded in that surf for 16 days and was pulled off thru the same surf , being picked up and dropped 8 to 12 feet off every wave. They then tightened the rigging and she was sailed back to BC, no serious damage .
    In a subsequent trip, she hit off Todos Santos, and the owner went to La Paz to party for a few days. By the time he got back, she was full of sand. As you can see, she was still basically intact, as was the case two years after the grounding. This was the hull that T-boned the steel barge at 8 knots. Do you see any buckling in the bow? And you say origami hulls are a not strong enough? How long would your "Lloyds Approved " fibreglass hull have lasted in these conditions? Two years ? ********. Not two hours!

    Thanks for posting the photos.

    You can take a 20 ton hydraulic jack, put it on any point of the tank top hull joint, and lift the entire hull from that point , or tie the hull down and crank the jack till it is rock hard , or put an extension on the handle and crank it until you blow a seal, and you will not make a noticeable deflection on the plate at that point. THAT is what supports the ends of the transverse webs , thru the gussets , not at one point , but at eight points around the hull, the forces being transmitted to the tank top edge thru the gussets, over a length of several feet, not point loads.
    8 times 20 tons, not strong enough on a boat a fraction that weight? Duuhhh!!

    If, as you suggest, you run the webs right to the centreline , you eliminate the option of building the water tank there, unless you want a tank that has totally inaccessible corners. Your math wont tell you anything about accessibility for maintenance. So were would you put the tank, which doesn't involve raising it's centre of gravity considerably, and taking up useful storage space on the boat?
    Evan had no problem using all his useful storage space for tankage, and raising the centre of gravity on his boat, given that he only left port once , and had huge storage space ashore. That kind of cruising lets one be as naive as one wishes.

    I heard on CBC radio today, a psychologist, saying that over reliance on computers to answer all ones questions, leads to a porportionate dumbing down of the user. Don' t use the common sense portion of the brain, and it atrophies. I feel I have been dealing with such atrophied common sense here for a while.
    Reminded me of the time I made a purchase which cost $3.25 . I gave the young girl at the checkout $5.25 and she ran off to find her pocket calculator.
    Or the guy on this site who tells us that his 38 ft Colvin steel boat will weigh 14,000 lbs, roughly the same weight as the wooden Pipe Dream by Francis Kinney, which has planking about a third the weight of his ten gauge hull plate, or decking which is less than a third of the weight of his ten gauge.
    Don' t tell us how much it weighs on paper, build her , then weigh her, then tell us,( if you have the huevos)
    Duuuhhh!!
    While I find Kinney's manual of calculations useful ( trapezoidal rule is as accurate as Simpson's multipliers according to Herreshoff, just not as exhibitionist) Kinney's obsession with numbers show the lack of common sense often involved. While he calculates the weight of the galley pump and its distance form the centre of buoyancy, and it's effect on trim, he estimates the total weight of all the personal possessions of three people at 129 lbs, but makes no mention of spare ground tackle, food, scuba gear, spare sails, etc etc
    Bear in mind that one Aussie said on Cruisers forum, he found many crane scales up to 750 kilos out of whack. I guess the only way to get an accurate weight is to run the boat movers trailer with the boat on it over a highway scale, then run the empty trailer over it.
    Another example of letting the math over rule common sense and do all our thinking for us, is the number of very expensive boats ,which do all the plumbing and electrical work ,then drop a solid hull liner in over the works. When something goes wrong , you have to to cut a hole in the liner, only after you have figured out exactly where the problem is. No math will deal with such problems , only common sense and practical experience. Such boats have a users instruction manual the thickness of a phone book.
     
  8. Brent Swain
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    Brent Swain Member

    You said yourself that they were your own design, the design you had before you beefed it up after it became apparent that they were not strong enough.

    Some designers won't correct a mistake no matter how obvious it becomes , for not having the huevos to ever admit a mistake.napoleon said it sometimes it takes a greater man to admit a mistake than to lead an army into battle. I don';t mind admitting I didn't know everything there is to know about a new technology the first time out.
    The selling of offsets which are the same as originally drawn, forcing the builder to correct them every time, is one common example. Being a start from zero experience with origami, we had a lot to learn, as is always the case with all new technology. Anyone who says he can a calculate everything on a first of prototype is lying.
    I told the builders of the 40 that the flat bar keel webs were not strong enough. It was in the plans at the time. They ignored the plans.

    That's my point, you revise your design after failures such as "keels being driven up into the hull" in your own words.




    They are scaled on the same principal of a pull together largely frameless shell. What works for a 21 footer isn't necessarily valid for a 36 or a 40 and invalid for a 57 or a 60 footer.

    That is why I designed each from scratch, except the 40 . The 36 wa so successful that I didn't see any point in changing the shape of that which had worked so well. It's common knowledge that you can scale up 12 %, max without changing things too much . I've always advised against scaling it up any more.

    Using statistics of all your 21 to 35.5 foot boats and excluding the failures doesn't prove anything.

    Three decades and hundreds of thousands of miles of failure free offshore cruising, proves the sceptics totally full of ****.
    What 21 footer? They have adult reading classes in most big cities , you know.



    Dudly dix pointed out what exactly and when ? Also Dudly is a good yacht designer not an engineer, so he follows ABS design rules. You don't. All you have left now your engineering misunderstanding has evaporated is tall tales from yourself about what happened to other people.

    In the last debate on origami boat building, several years ago, Dudley Dix pointed out that years of offshore cruising in any design, without structural failure ,is proof of structural adequacy, beyond any mathematical calculations

    Your engineering knowledge is abysmal and demonstrably proven so by your own design failures.

    What failures?



    Rotating keels into hulls is not a feature, its a failure. You had to revise your design, after it became apparent. Had you understood some basic principles you could have avoided that initially. I was commenting onthe process you adopt which is Trial and error design.

    All new technologies have an element of trial and error. The only way to avoid that, is to never try anything new.
    In the shop where I built my first origami boat, a 26 footer, a shipwright was building a traditional wooden boat. He took a year to set up his frames. He kept asking "Why do people want to keep re- inventing boat building?"
    I pulled together the 26 foot hull , decks, cabin, cockpit , keels, skeg rudder, lifelines chainplates, mooring bitts, handrails, cleats, mast step , hatches, in effect fully detailed in 21 days . Then I asked him Nnow have you figured out why people wan to re - invent boat building?'
    Later ,the fully qualified shipwright asked me if I would build him a steel boat.

    On the other thread where we were trying to get you to discuss structures, it was clearly stated that your 36 design has inherant unecessary weakness, and severe stress raisers which are likely to cause fatigue failure at some stage in the vessels life if it's used at sea.

    I've covered that many times in this discussion, in practical terms, which thus put them beyond your comprehension.



    Says who? can you draw me a SN curve ? do you understand fatigue? if you do you are being very evasive, otherwise you are just ignorant of the actual process.


    You can't determine when that failure occurs or what the extent of the damage will be. Since there is no redundancy in your structure it could be seriously catastrophic, for example, if it's in the middle of a severe storm.




    I have said repeatedly that you can add a day or two and a hundred or two dollars worth of material and do the job properly. But your response is this:



    Be sensible, you could add a proper set of floors from plate offcuts. A few flat bar transverse frames would add a few hundred at the most.

    While you disregard all concern about safety, couldn't give a toss about the people and their safety. And won't even look at the very serious structural issues raised.



    Until the tail falls of the aircraft, or the bridge collapses its safe, that's not an argument for poor design.[/QUOTE]
     
  9. Brent Swain
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    Brent Swain Member

    With a book ,and plans it won't be a problem. Before I wrote the book,I'd sit down with the builder and tell them what was happening in the photos, and they would record it . No one had any problem building that way.Now, with the book, you have far more info. No one has had any problem building their own with book and plans, and they tell me that every question they had, they found the answer in the book and plans.
     
  10. Brent Swain
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    Brent Swain Member

    No, I don't have the ability to post pictures out in these islands. I don't sail junk rigs.
     
  11. Brent Swain
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    Brent Swain Member

     
  12. Brent Swain
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    Brent Swain Member

    The 36 in post 205 and 206 has done the run from BC to Mexico, Hawaii and back to BC, and T boned several BC reefs at hull speed, no damage, despite having the keel supports in the drawing posted. Her skipper is very experienced.
     
  13. LyndonJ
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    LyndonJ Senior Member



    The bit starting with NEV and ending in ER apparently :)
    Sorry I'm 5 feet out I see its 26. It was a leading question. I was interested in the facts. It's hard to know what to believe about your anecdotes at times.

    The grounded boat was a single keel though, not a twin keel. It may have been quite a different story of the twin keel had been dropping onto her keels. It was the twin keel that was poorly detailed.

    Twin keels are the hardest to get off a beach too I've been told.

    This is still no reason to not lift your standards.

    I also don't believe for a second that your 36 design built to your plans could gain CE cert.

    I use computers all day some days, but it takes a lot of skill and brains and thinking to do it. Sounds like more smoke and mirrors logic of yours.
     
  14. Wynand N
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    Wynand N Retired Steelboatbuilder

    BS, stop talking bull **** man.....we get tired of your same lament over and over about your origami boats.

    I think Dudley (who happened to be a good friend of me when he was still living in South Africa, he visited my yard once a month and I commissioned his 38 ft design in 1991 then known as the Force 38) would be interested in your ridiculous claim in the 2nd paragraph quoted.

    Dudley did in fact worked in the steel engineering field whilst studying for his boat designer's Diploma at Westlawn before going professional full time after obtaining that Diploma. Have you ever see the syllabus of Westlawn?

    You are quite right he follows ABS rule as a minimum standard and his designs are well engineered, although you claim he is no engineer. Quite so, but at least he is using scantling rules that are calculated and proven over many years which makes his designs well accepted by builders and owners.
    Since you are no engineer and I wil repeat myself again as I did in the past which brought me a lot of flack from your disciples, you are a hillbilly. Why do you not use ABS or any other Society scantling rule with your designs?? Or perhaps you have no concept how to use the numbers and maths.
    If this is the case, do take up my suggestion in post #217

    About Dudley building and sailing his own boats; you quite right he did but what you fail to mention BS, is that he had built only plywood boats for himself which are well engineered. His successful racers "Black Cat" and 'Didi" come to mind. You can actually see photos of these builds in his backyard on his website.

    As for his steel designs; I can vouch for some of them as I had built a 30ft Houtbay, 38ft, 43ft, 57ft, 65ft to his designs and some of my builds also on his webpage.
    Not so long ago you actually bad lipped his designs on this very forum if I am not mistaken and the rip off of these building techniques to the owners pocket, so why the change of heart?

    Finally, why bring a reputable designer using proper scantling rules into this when you and your designs are questioned. Stand up for yourself or leave....cowboys don't cry.
    As I said in post #217, your call. Please take it up and prove us wrong :confused:
     

  15. terhohalme
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    terhohalme BEng Boat Technology

    What is stronger? I am conserned of the shear stress at the bottom plate and possible fatique failure. Is the bottom plate thick enough and topside welding strong enough for this? The essential question here is: How is this strut detail designed in your drawings? This builder did not tied it to the topsides. Did this builder made it right, according to your drawings?

    Strongall and Lundstrom boats are not your design. Perhaps you should consult them?

    Terho
     
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